This invention relates to surgical fastener applying apparatus, and more particularly to surgical fastener applying apparatus of the type which applies surgical fasteners to body tissue clamped between relatively movable fastener holding and anvil parts of the apparatus.
Several types of surgical fastener applying instruments are known for applying surgical fasteners to body tissue clamped between relatively movable fastener holding and anvil parts of the apparatus. See, for example, Hirsch et al. U.S. Pat. No. 3,275,211. The surgical fasteners may be either metal staples as shown in the Hirsch et al. patent, or they may be non-metallic resinous materials as shown, for example, in Green U.S. Pat. No. 4,402,445. In the case of metal staples, the staple legs are typically driven through the tissue and clinched by the anvil to secure the staples in the tissue. In the case of non-metallic fasteners, each fastener may initially consist of two separate parts: a fastener part disposed in the fastener holding part of the apparatus, and a retainer part disposed in the anvil part of the apparatus. The leg or legs of the fastener parts are driven through the tissue and interlock with the retainer parts to secure the fasteners in the tissue. Although most metal surgical staples are biologically inert and therefore remain permanently in the body, biologically absorbable metal surgical staples are known. Surgical fasteners of non-metallic resinous materials can also be made either biologically absorbable or non-absorbable.
The type or form of the fasteners employed forms no part of the present invention. The various types of fasteners are mentioned solely to establish that the term "surgical fastener" as used herein is generic to all of these types of fasteners, and to similarly establish that the terms "fastener holding part" and "anvil part" as used herein are also generic to instruments for applying all of these various types of fasteners.
In most of the known instruments for applying surgical fasteners to tissue clamped between the fastener holding and anvil parts of the instrument, the distal fastener applying assembly (which includes the fastener holding and anvil parts) of the instrument is rigidly connected to the proximal actuator portion of the instrument. This is true, for example, of the instruments shown in the above-mentioned Hirsch et al. and Green patents.
Recently, however, there has been increasing interest in instruments in which the connection between the fastener applying assembly and the actuator assembly is not completely rigid. For example, Noiles et al. U.S. Pat. No. 4,473,077 shows a surgical stapler in which the shaft assembly connected between the fastener applying and actuator assemblies is transversely flexible in one plane (i.e., the plane of the paper in Noiles et al. FIG. 5). This may be a desirable feature in an instrument of the type shown by Noiles et al. which is intended for insertion into a tubular body organ. In such applications the flexible shaft of the instrument conforms to the curvature of the surrounding body organ. However, in instruments which are not usually supported by surrounding body structures (e.g., instruments of the type shown in the above-mentioned Hirsch et al. and Green patents), excessive flexibility in the instrument between the fastener applying and actuator assemblies may mean that the position of the fastener applying assembly cannot be controlled from the actuator assembly and that each of these assemblies must be separately supported during placement of the instrument on the tissue to be fastened. This may mean that two people are required to handle the instrument during placement and removal.
In view of the foregoing, it is an object of this invention to provide surgical fastener applying apparatus of the type described above in which the fastener applying assembly is not rigidly connected to the actuator assembly but in which the location of the fastener applying assembly can be substantially controlled from the actuator assembly.
It is another object of this invention to improve and simplify surgical fastener applying apparatus of the type described above in which the fastener applying assembly is not rigidly connected to the actuator assembly.